Because of their prominent role in life processes, enzymes continue to be a focal point of interest among those concerned with the mechanisms whereby enzymes function. Numerous enzyme catalyzed reactions involving carbon acid prototropy include many utilized in fatty acid and in carbohydrate synthesis and metabolism. Following the traditional chemical approach of studying simpler models of complex systems with the purpose of extrapolating via analogy to the complex enzyme systems, we propose to determine mechanisms of prototropy between carbon acids (bases) and acceptor bases (acids) by utilizing kinetics technics. Specifically it is proposed to (1) gather various kinetics data for the acid catalyzed hydration of various unsaturated thiolesters and unsaturated ketones, (3) compare the thiolester and ketone carbonyl groups from the viewpoint of their affect on prototropic reactions which occur at the alpha carbon with the goal of better understanding the apparent ketonic character of thiolester groups, (4) examine metal ion catalysis of prototropy among phosphoketones and alpha-ketoacids, (5) examine selected enzyme catalyzed reactions of ketones with a view to combining the results of model studies with analogous enzyme studies for the purpose of better understanding the nature of prototropy among ketonic substrates in enzymatic reactions.